In the field of electronic circuit design, analog switches are used in a wide variety of applications, including, but not limited to, radio-frequency (RF) multiplexers, demultiplexers, passive mixers, switched-capacitor circuits, etc. Analog switches are designed to couple an analog signal at a first node to an analog signal at a second node. In an “on” state, the switch may directly couple an analog voltage or current at the first node to the second node, while in an “off” state, the switch may isolate the analog voltage or current at the first node from the second node.
In general, a high performance analog switch must meet several, possibly conflicting, design objectives. First, during the on state, the switch should provide low series impedance between the first and second nodes. Second, during the off state, the switch should provide a high series impedance between the first and second nodes. Furthermore, to minimize signal attenuation at high frequency, the switch should introduce minimal parasitic capacitance to the first and second nodes.
It would be desirable to provide novel and effective techniques to meet the objectives for designing a high performance analog switch.